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6.0 Operation
6.1 Powering up the system
6.1.1 Before switching on
We suggest that you adopt this safety routine when operating the system for the first time, or following
any re-configuration:
Check that all connections are secure.
It is important that your system should be able to monitor the output of the detector modules to prevent
inadvertent over-driving.
o Is the data acquisition system (hardware and software) working correctly?
o Is the oscilloscope (if used) connected and set up correctly (including the triggering)?
Check that the main power switch on the front panel is “OFF” (i.e. not depressed).
Check that the mains-to-DC power supply is correctly connected and switched on.
Check that the filter cube compartment door is properly closed – is the knurled screw tight and is there
no gap between the door and the optical block body?
Turn off any microscope illumination source. This is especially important if the illumination contains
any visible light at wavelengths shorter than 680 nm because this can enter the detection system
directly via the objective lens and over-load the PMTs.
Turn off any un-necessary lights, and / or cover the equipment.
Block the laser beam (possibly using a shutter) until you are ready to acquire images.
Make sure the safe/imaging lever is in its left-hand “safe” position.
6.1.2 Switch-on routine
On the controller front panel, set the “Master Safety” toggle switch to the “safe” position by pulling
gently on the toggle and lifting it upwards.
Turn both high-voltage controls fully anti-clockwise to minimum.
On the optical block, move the laser / visible dichroic mirror into the beam by rotating the front-mounted
control lever left until it stops. The optical collection system is now opened to receive light.
Turn on main power at the controller using the push-button switch at the left of the case.
o Both meters and the Scientifica logo should illuminate.
o Both meters will read a small voltage, usually positive. The value has no significance.
When you are ready, set the toggle switch on the controller to the “Enable” position. The detector
gains can now be adjusted using the two rotary controls.
o Adjusting either rotary control clockwise will increase the high voltage and thereby the gain
of the detector. Adjust the controls gradually.
o The corresponding panel meter should change to show the actual voltage applied to the
PMT (up to a maximum of just over -1000V). The negative polarity reflects the way in which
the PMTs are operated.
NB: If no change in applied voltage is seen, then it is possible that one of the safety interlocks has been
activated. Check that the filter cube door is closed tightly and that the lever on the front of the optical block is
fully clockwise. If no reading is seen after these checks, refer to the troubleshooting section in the appendix.
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